CONTAMINATION LEVEL OF PROCESS HELIUM, INTERNAL PURIFIER. Presently, LASA cryogenic plant has its gas storage system divided in two parts operating with the helium gas being in a not-purified or purified state. The former corresponds to the helium gas as recovered from experimental users that has been processed through oil removal and drying cartridges stage. It has a typical level of total condensable contaminant of between 1 % and 2 % in volume. The latter instead, corresponds to the process where the helium gas is fed into the current liquefier, through a cryogenic purifier. An overall contamination, better than 50 ppm is guaranteed by the purifier, by means of a complex manual gas handling. It is foreseen to remove the current cryogenic purifier from the main process and supply the new liquefier directly with the not-purified gas, thus reverting the storage system to a single gas type. For this reason, the Bidder must ensure that the liquefaction system can safely work with contaminated gas up to total condensable contaminants level of 10% by volume. - Operational cold-box runtime in each scenario in case it is time-limited. Safe operations with contaminated helium gas may be achieved by different means according to Bidder preference (internal purifier, cold traps, or others) provided that the liquefier operation is fully transparent to final user. The management of internal purification system must be fully autonomous and integrated within cold-box control system.
